/*
 * Copyright (C) 2017-2019 Dremio Corporation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.dremio.resource;

/**
 * Observer for updates during resource scheduling/allocation.
 */
public interface ResourceSchedulingObserver {
  /**
   * Called to report the beginning of engine start.
   */
  void beginEngineStart();

  /**
   * Called to report the beginning of queue wait.
   */
  void beginQueueWait();

  /**
   * No-op implementation.
   */
  ResourceSchedulingObserver NO_OP = new ResourceSchedulingObserver() {
    @Override
    public void beginEngineStart() {
    }

    @Override
    public void beginQueueWait() {
    }
  };
}
